1. Faculty of Science, School of Sciences, Natabua Campus Lautoka
BIO706 Embryology Lectures: 13 Evolution of seed plants - II

2. Kingdom Plantae

3. Angiosperms are flowering plants that form seeds inside a protective chamber called an ovary.
Examples: 
Monocots: Orchids, lilies, grasses, palms, bamboo
(Eu)dicots: Daisies, maples, snapdragon, pea, oaks

4. Angiosperms (Flowering Plants)
Systematists are identifying angiosperm clades.
Originally, only:
                       
Monocots are angiosperms that possess one embryonic seed leaf (cotyledon).

5. Dicots are angiosperms that possess two embryonic seed leaves (cotyledons).
However, angiosperms have recently been divided into new taxonomic groups.

6. A comparison of monocots and dicots

8. The flower is the defining reproductive adaptation of angiosperms
                       
Flowers are made up of four types of modified leaves à sepals, petals, stamens, and carpels.
                                   
a.  Stamens are the male reproductive organs that produce microspores.
b.  Carpels are female reproductive organs that produce megaspores.

9. The structure of a flower.

12. Pollen-grains of Angiosperms

13. A fruit is a mature ovary
                                   
Protect dormant seeds.
Fruit aids in seed dispersal.
                     - Wind dispersal
                     - Attachment and transportation
                     - Consumption – berries contain seeds to be passed in feces

14. Fruit adaptations that enhance seed dispersal

17. Life cycle of an angiosperm
                       
Mature plant is the sporophyte
Some plants easily self-pollinate, but most have mechanisms to ensure cross-pollination. 
Male gametophytes reach female gametophytes by producing a pollen tube.
Next slide: The life cycle of an angiosperm.

19. Angiosperms dominated the earth at the end of the Mesozoic era
                       
Radiation of angiosperms represents the transition from Mesozoic to Cenozoic
Angiosperms and animals have affected one another’s evolution

20. Coevolution is the mutual influence on the evolution of two different species interacting with each other and reciprocally influencing each other’s adaptations.
                                   
e.g., Pollinator-plant relationships

22. Plants and Human Welfare
Agriculture is almost totally dependent on angiosperms.
Plant diversity is a non-renewable resource.
                       
Many medicines are obtained from plant materials.

25. Deforestation is an international practice

28. Deforestation in the United States

29. Fragmentation of a forest ecosystem

30. A sampling of medicines derived from plants

31. Questions are welcome